The present invention relates to a device for actuating in rotation a mechanism by means of a control shaft mounted to rotate about its axis in a support, and which comprises elastic means for applying to the control shaft a reaction torque the magnitude of which is a function of the angle of rotation of the shaft.
Devices of this type are known in which a reaction torque is applied to the shaft, for example by causing it to raise a weight or stress a spring in the course of its rotation. It is in particular known to mount on the shaft a spring which is coiled around the axis of the shaft, fixed on one hand to the shaft itself and on the other hand to the support. With this arrangement, a reaction torque is obtained which is substantially proportional and of opposite sign to the angle of rotation of the shaft relative to the support. The sole solution known for modifying the law of variation of the reaction torque as a function of the angle of rotation consists in modifying the ratio of proportionality by changing the spring.